1)
Why did they not recognize the Kol of Simchah?
1.
Rashi: It was due to the voice of those crying, which was heard further than the Teru'ah of Simchah.
2.
Malbim #1: It was not recognized that some cry (because they build with Koresh's permission, and not miraculously) for the same reason that others rejoice (since it is with permission, the Kedushah will be permanent). This is like Drush.
3.
Malbim #2: The Kol of Teru'ah was louder than the Kolos of Simchah and crying, so the latter were not recognized. This is the simple meaning.
